Where most architects these days can use floor to ceiling glass, Passive House windows are very expensive. Where many buildings have jogs and other architectural elements that can add visual excitement, every jog on a Passive House has a cost, so they do tend to be boxy. It becomes an exercise in proportion and careful placement of the few elements that the architect has to play with; Passive House architect Bronwyn Barry has a hashtag to describe it when done right: #BBB or “Boxy But Beautiful.”

I also suggested that “if we are going to ever get a handle on our CO2, we are going to see a lot more tall urban buildings without big windows, without bumps and jogs. Perhaps we might even have to reassess our standards of beauty.”

Perhaps I spoke too soon, because Germán Velázquez of VArquitectos has designed what is now the world’s tallest Passivhaus structure in Bilbao, and it is a looker.

The Bolueta building is 88 meters (289 feet) tall with 28 floors above grade, beating out Cornell by a bit to be the tallest Passivhaus building in the world. It looks really expensive but in fact, came in on budget, though to be fair, Europeans do budgets that allow architects to design nice buildings, even for social housing. "Now that Bolueta is complete, there are no excuses anymore: it is possible to realise such a project in Bolueta, and it is just as possible to realise one almost anywhere out there," says Velázquez.

The façade of the tallest Passive House high-rise in Bilbao is also striking. The surrounding buildings and countryside are reflected in the black, glossy surfaces. "The project has a significantly "lighter" effect as a result, and the black colour symbolises the industrial past of the city. It is a tribute to the two-and-a-half century’s old heavily coal-based industry," explains Velázquez. The second tower will be grey in colour to allude to the steel that was once produced in Bolueta.

Through its choice of materials and the wavy pattern of installation, the fact that the windows are a relatively small proportion of the facade is less of an issue; it is a really dramatic skin. It is a beautiful box.

Passivhaus is hard. Beautiful, dramatic Passivhaus is harder. I said earlier that “we might even have to reassess our standards of beauty.” Germán Velázquez of VArquitectos proves me wrong. This building will be the start of a new kind of Bilbao effect -- the standard by which buildings are judged.